RT9501A/B Advanced Lithium-Ion Linear Battery Charger General Description Features The RT9501 is a single Lithium-Ion or Lithium-Polymer cell linear battery charger which is designed for compact and cost-sensitive handheld devices. It combines charge status indication, charge termination, battery temperature monitoring, and high accuracy current and voltage regulation in a MSOP-8 package. z For Single Lithium-Ion or Lithium-Polymer Cell Battery Pack (4.1V or 4.2V) z A Few External Components are Required Precharge, Constant Current, Constant Voltage Modes Battery Temperature Monitor Charge Status Indication Automatic Battery Recharge Charge Termination Detect Auto Low Power Sleep Mode when VDD Power is Removed MSOP-8 Package RoHS Compliant and 100% Lead (Pb)-Free The RT9501 charges the battery in three modes, precharge, constant current, constant voltage. If the battery voltage is below the precharge threshold VO(MIN), the RT9501 precharges the battery with a lower conditioning current. After precharge, the RT9501 applies a constant current to the battery. An external senseresister sets the charge current. The constant voltage mode continues until the battery reaches the regulation voltage. The battery temperature is continuously measured by an external thermistor through the TS pin. The RT9501 inhibits charge until the temperature is within the range defined by users. Ordering Information RT9501 Package Type F : MSOP-8 Lead Plating System P : Pb Free G : Green (Halogen Free and Pb Free) Voltage Version A : 4.1V B : 4.2V Note : Richtek products are : ` RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. ` z z z z z z z z Applications z z z z Digital Cameras PDAs Cellular Phones Information Appliance Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. Pin Configurations (TOP VIEW) VDD TS STAT GND 1 8 2 7 3 6 4 5 BATT CS FB/CE CC MSOP-8 Suitable for use in SnPb or Pb-free soldering processes. DS9501A/B-09 April 2011 www.richtek.com 1 RT9501A/B Typical Application Circuit D1 VIN Q1 RCS Battery Pack C2 0.1uF to 1uF R4 1k + NTC 5 CC FB/CE 6 7 CS 1 BATT 8 4 RT1 2 VDD GND TS STAT 3 C1 0.1uF RT2 R3 2k GND Figure 1. Application circuit using P-Channel MOSFET VIN RCS Battery Pack Q1 C2 0.1uF to 1uF R1 1k + NTC 5 7 1 CC FB/CE 6 CS BATT 8 TS STAT 3 VDD 4 GND C1 0.1uF GND RT1 2 R3 2k RT2 Figure 2. Application circuit using PNP transistor www.richtek.com 2 DS9501A/B-09 April 2011 RT9501A/B Functional Pin Description Pin Name Pin Function VDD Supply Voltage Input. TS Temperature Sense Input. Input from battery temperature monitoring circuit. STAT Charge Status Output. 3-state status indication of charge, charge complete and temperature fault or disable or sleep mode. GND Ground. CC Charge Control Output. Current output to drive on external PNP transistor or P-Channel MOSFET for current and voltage regulation. FB/CE External Feedback Input or Charge Enable Function. Input from controller or finely adjust the battery regulated voltage with external voltage divider. CS Current Sense Input. Charge current is sensed according to the voltage drop from supply voltage to this pin. BATT Battery Voltage input. Input directly from battery voltage. Function Block Diagram - BATT VDD Sleep Mode Detection + VDD CC Control - Internal FB FB/CE Feedback Determination & Enable Control CV Control Precharge Control Logic + Recharge CS VREF1 FB2 VREF2 + + TS2 Trip + + TS1 Trip - TS FB2 + FB2 VREF3 FB2 VREF4 CC VDD STAT GND FB2 DS9501A/B-09 April 2011 www.richtek.com 3 RT9501A/B Absolute Maximum Ratings z z z z z z z (Note 1) Supply Voltage --------------------------------------------------------------------------------------------------------- −0.3V to 7V Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°C Power Dissipation, PD @ TA = 25°C MSOP-8 ----------------------------------------------------------------------------------------------------------------- 300mW Package Thermal Resistance MSOP-8, θJA ------------------------------------------------------------------------------------------------------------ 80°C/W Operation Junction Temperature Range -------------------------------------------------------------------------- −40°C to 125°C Junction Temperature ------------------------------------------------------------------------------------------------- 150°C ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V Recommended Operating Conditions z z (Note 3) Supply Input Voltage -------------------------------------------------------------------------------------------------- 4.5V to 7V Junction Temperature Range ---------------------------------------------------------------------------------------- −20°C to 70°C Electrical Characteristics (TA = 25°C, unless otherwise specification) Parameter Symbol Test Condition Min Typ Max Units Operating Current IDD(OPE) 4.5V < V DD < 7V, Excluding external loads -- 1 2 mA V DD Sleep Current IDD(SLP) VBATT −VDD ≥ 0.2V -- -- 3 μA Input Bias Current @ BATT pin IBATT VBATT = VO(REG), VBATT − VDD ≥ 0.2V -- 1.5 2.5 μA Input Bias Current @ CS pin ICS VCS = 5V, VBATT − VDD ≥ 0.2V -- -- 1 μA Input Bias Current @ TS pin ITS VTS = 5V, VBATT − VDD ≥ 0.2V -- -- 1 μA Input Bias Current @ FB/CE pin ICE VCE = 5V, VBATT − VDD ≥ 0.2V -- -- 1 μA Input Low Voltage @ CE pin VCE -- -- 1.5 V Input High Voltage @ CE pin VCE VDD–1.5 -- -- V Feedback Voltage @ FB pin VFB 2.048 2.10 2.152 V Output Voltage VO(REG) RT9501A 4.059 4.10 4.141 V RT9501B 4.158 4.20 4.242 V Current Regulation Threshold VI(SNS) 100 110 121 mV Charge Terminated Current Detect Threshold V(TERM) 2 12 22 mV Lower Temperature Threshold VTS1 29.1 30 30.9 %VDD Upper Temperature Threshold VTS2 58.3 60 61.8 %VDD Precharge Threshold VO(MIN) 2.8 2.9 3.0 V Precharge Current Regulation V(PRE) 4 14 24 mV Recharge Threshold VO(RCH) www.richtek.com 4 VI(SNS) = V DD – VCS VO(REG) – V O(REG)– V O(REG) – V 140mV 100mV 60mV To be continued DS9501A/B-09 April 2011 RT9501A/B Parameter Symbol Test Condition Min Typ Max Output (Low) Voltage @ STAT pin VSTAT(LOW) IOL = 10mA -- 0.4 0.6 Output (High) Voltage @ STAT pin VSTAT(HIGH) IOH = 5mA VDD –0.5 -- -- Units V Output Low Voltage @ CC pin VCC(LOW) IO(CC) = 5mA ( sink ) -- -- 1.5 V Sink current @ CC pin ICC(SINK) Not to exceed power rating specification (PD) 5 -- 40 mA Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution is recommended. Note 3. The device is not guaranteed to function outside its operating conditions. DS9501A/B-09 April 2011 www.richtek.com 5 RT9501A/B Application Information Charge Profile Precharge mode Constant current regulation mode Constant voltage regulation and charge termination mode Recharge mode Regulation voltage Recharge voltage Regulation current Precharge threshold voltage Precharge current = Charge termination current Figure 3. Typical charge profile Detection Constant Current Regulation Charge Mode First, the FB/CE pin must connect to VDD or a voltage divider to enable the charge function. And then if a battery is already inserted and the input power source is absent, the RT9501 will enter sleep mode to prevent draining power from battery. When input power source and battery are both existed, another detection is the battery temperature. The TS pin voltage must be in the allowed range as shown in Figure 6 and the electrical characteristics, and then the RT9501 will start the charge cycle according to the battery voltage conditions. When the battery voltage is between the precharge threshold VO(MIN) and the regulation voltage VO(REG), the RT9501 starts the constant current regulation charge mode. RT9501 monitors charge current with voltage drop between two terminals of a sense-resistor, RCS, which connects to pin VDD and CS. The following equation can calculate the desired charging current. IO(REG) = Precharge Mode When the battery voltage is lower than the precharge threshold VO(MIN), the RT9501 begins to charge the battery in precharge mode. In this condition, the precharge current is set at approximately 10% of the constant regulation current. The purposes of small precharge current are to minimize the power dissipation on the external switch during the precharge period and to revive deeply discharged battery cells. www.richtek.com 6 VIN VI(SNS) RCS RCS Q1 Battery R4 CC FB/CE CS BATT VDD GND TS STAT Figure 4 DS9501A/B-09 April 2011 RT9501A/B Constant Voltage Regulation and Charge Termination Mode When the battery voltage reaches the regulation voltage VO(REG), the constant voltage feedback control starts, and then the charge current begins to decrease as the typical charge profile shown. As the charge current decreases to lower than charge terminated current threshold, the RT9501 will terminate the charge cycle. VIN RCS Battery Pack Q1 R4 RT1 + C2 FB/CE CS CC BATT VDD STAT RT2 TS GND Thermistor Figure 5 Recharge Mode After the charge termination mode, if the battery voltage falls to lower than the recharge threshold voltage VO(RCH), the RT9501 will begin a new charge cycle according to the battery voltage. VDD Temperature Fault Range VTS2 Normal Temperature Range VTS1 Battery Temperature Detection The RT9501 continuously detects the battery temperature by measuring the TS pin voltage. A NTC or PTC thermistor can parallel with RT2 to deviate the TS pin voltage. (As shown in Figure 5) The TS pin voltage must be within normal temperature voltage range that is shown in Figure 6 and electrical characteristics, and then RT9501 can start working normally. The RT1 and RT2 can be derived from following equations. For NTC Thermistors: RT1 = RT2 = 5 × RTH × RTL 3 × (RTL - RTH) 5 × RTH × RTL Temperature Fault Range GND Figure 6 FB/CE Pin Functions This pin has two functions, one is to enable/disable the charge function, and the other is to finely adjust battery regulation voltage. Connect this pin to VDD to enable RT9501, and connect to ground to disable it (Figure 7). If this pin is connected to a voltage divider as shown in Figure 8, it can be a 2.1V reference voltage to adjust the output regulation voltage as desired. [(2 × RTL) - (7 × RTH)] RCS VIN For PTC Thermistors: RT1 = RT2 = 3(RTH - RTL) [(2 × RTH) - (7 × RTL)] Where RTL is the resistance value in lowest desired operation temperature and RTH is the resistance value in highest desired operation temperature. The resistances of thermistors are specified by the thermistor manufacturer. If the temperature monitoring function is not desired, there's an easy method to set RT1 and RT2 at the same value and disconnect the thermistor to disable this function. DS9501A/B-09 April 2011 Battery RCE 5 × RTH × RTL 5 × RTH × RTL Q1 R4 GPIO CE CC CS BATT VDD STAT TS GND Figure 7. For CE pin Function www.richtek.com 7 RT9501A/B VIN RCS Q1 Battery R4 RFB1 FB CC CS BATT VDD STAT RFB2 TS GND Figure 8. For FB pin Function VO(REG) = 2.1× (1+ RFB1 RFB2 Selecting Input/Output Capacitor In analog circuit applications, to place a high-frequency decoupling capacitor nearby the controller IC between input power source and ground is very important. A 0.1uF ceramic is recommended. If a high ripple and noise input power is chosen, it should have enough capacitance to reduce the disturbance. A 0.1uF to 1uF output capacitor is recommended to control the output voltage and keep the output voltage ripple small when the battery is disconnected. ) V Charge status indication The RT9501 indicates the status of the charger on the 3state STAT pin. The following table shows the statuses of this pin. Condition STAT Pin In battery charging cycle High Charge cycle completed Low Temperature fault or charge function disable or sleep mode High Impedance Selecting an External PNP Pass-Transistor or P-Channel MOSFET: The RT9501 drives an external PNP transistor or P-Channel MOSFET to control the charging current. The specifications must be concerned are the voltage and current rating and package power dissipation. The external switch is performed as a linear regulator. The maximum power loss occurs when the constant current regulation starts at the beginning, and it can be calculated approximately from following equation: P D(MAX) = I(SNS) × (V DD - 0.1V - 2.8V) I(SNS) is the constant regulation current. The minimum voltage drop between the sense-resistor is 100mV, and the minimum precharge threshold voltage is 2.8V. The external pass device with PCB heatsinking must be rated for the maximum power dissipation. www.richtek.com 8 DS9501A/B-09 April 2011 RT9501A/B Outline Dimension D L E1 E e A2 A A1 b Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.810 1.100 0.032 0.043 A1 0.000 0.150 0.000 0.006 A2 0.750 0.950 0.030 0.037 b 0.220 0.380 0.009 0.015 D 2.900 3.100 0.114 0.122 e 0.650 0.026 E 4.800 5.000 0.189 0.197 E1 2.900 3.100 0.114 0.122 L 0.400 0.800 0.016 0.031 8-Lead MSOP Plastic Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 5F, No. 95, Minchiuan Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)86672399 Fax: (8862)86672377 Email: [email protected] Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek. DS9501A/B-09 April 2011 www.richtek.com 9